Who fought in the crusades?

Answer 1

The Christians of Europe led the Crusades, and sometimes their holy rulers or kings would lead them in battle. An example of this would be Pope Urban II on the first crusade. They were waged against the Muslims, Russian and Greek Orthodox Christians, Mongols, Cathars, Hussites.

Answer 2

In 1095 Pope Urban II proclaimed the First Crusade at the Council of Clermont. He encouraged military support for the Byzantine Emperor Alexios I against the Seljuk Turks and an armed pilgrimage to Jerusalem. The enthusiastic response across all social strata in Western Europe established a precedent. Volunteers became crusaders by taking a public vow for various reasons: mass ascension into Heaven at Jerusalem, satisfying feudal obligations, the opportunity for glory and honour, or for economic and political gain. Four Crusader states were established, generally known collectively as the Outremer: the County of Edessa, the Principality of Antioch, the Kingdom of Jerusalem and the County of Tripoli. The crusaders were eventually pushed back, and after a mainland presence of nearly two centuries, the last city Acre fell in 1291. The Reconquista, the struggle between the Christians and Muslims in the Iberian Peninsula, was proclaimed a crusade in 1123 and ended with the fall of Emirate of Granada in 1492. The Northern Crusades that brought the pagan tribes of north-eastern Europe under Christian German, Danish or Swedish control were considered crusades from 1147. Pope Innocent III began the practice of the papacy proclaiming political crusades against disobedient Christian rulers in 1199. From 1208 in Languedoc, crusading was used against heretics. This continued in Savoy and Bohemia in the 15th century and against Protestants in the 16th century. Crusading was used in response to the rise of the Ottoman Empire in the mid-14th century, only ending with the War of the Holy League in 1699.